Homebrew Pinball #3, Part 80

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



Had a small get together at my place last weekend, and had the game set up and playable during that time, with a camera on it. I recorded about 12 hours of video, although some of that time it probably wasn't being played... Twice I had the solder break on the flipper wiring to the resistors. I'll need to think of a better way to mount those. Currently they're just hanging awkwardly from the coils from when I first attached them for testing, which obviously is bad. Once the flippers just died randomly, and came back next ball. Not sure if that was a tilt or something correct that the player didn't notice, or if something malfunctioned. Will have to track it down in the recording and see. One time the ramp switch didn't register, which has been a recurring issue. I've got it tweaked 'just right' so it's 99% good, but I need to figure out a better solution eventually. This wouldn't be too big of an issue, except the lock post in the ramp won't let the ball back down, since it doesn't know it's there. I had two other stuck balls, both times they were caught by the shooter lane diverter, pressed against the back of the drop target next to it. Both of these issues will at least be alleviated by a ball search, which I'd never gotten around to coding before. So the next day I added one in. Not too complicated... I shouldn't have put that off so long. Besides from that I had no reported issues, although I'm sure a lot of that was people just not knowing how the game is supposed to work.

Another thing that's been on the todo list for a long time: adjustable GI. When I originally got the led strips, I got some super bright 12V ones since I was worried about how well they'd work. Although the center of the playfield is still a bit dark if you turn off all the other lights in the room, overall it's more playable than some games, but in a lit room they're a bit much. Usually more light would always be better, but they tend to make it harder to see some of the mini displays, especially the ones along the edges. I considered trying to hook them up to a solenoid driver, and manually PWM them to get them to dim, and also give me manual control of them in the code (although I don't really know when I'd use that), but that sounded like it could be a bit of a pain (and who knows if my mosfets can handle that much current), so instead I ordered a cheap 12V LED dimmer off eBay.
It had these annoying bullet plugs that a lot of electronics have, but I've never had a good way to deal with. I was about to go about my usual process of cutting off the plugs, then buzzing out the wires to figure out which is which, and heat shrinking some new wires onto it, when I had a light-bulb moment: what if I just opened it up? Sure enough, two phillips screws on the back were all that was needed to open the case and see four nicely color coded wires soldered to spots on the board
A little bit of soldering, and I now had my own wiring and connectors attached
The dimmer works great, and I now have fine tuned control of the brightness of the GI (and can even turn it off if needed). Still need to find some way to mount this in the cab, but that'll be an issue for later on. At some point before the weather gets too cold I'd like to take the game apart, clean the inside of the cab and put in some final cable management for everything, then sand and stencil the cab with some playing cards.

While I was in the game I also took the opportunity to wire up a few more inserts: 3 in the center of the playfield to show your progress towards a potential wizard mode, and two more in the mini playfield. I stopped using the star rollovers I had installed there to sense the ball a while ago when I made the new diverter, and luckily I was able to find some white inserts that were the same diameter as the star rollovers to replace them with, so now I finally removed the switches and wiring underneath too.

Posted Tuesday, November 16, 2021
at 11:44 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 79

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



One of the issues I kept running into with the plastic covers was the rollover buttons. My 'free floating' 3d printed ones had ended up working pretty well, but sometimes they'd cause hangups with slow moving balls if the button was also stuck at an angle. In my quest to solve all potential ball trap points, something needed to change. Then someone on the slack channel mentioned these inductive proximity sensors:

Given their side and range, plus the fact that I don't have a wooden playfield in the way, these seemed like a good way to avoid having to deal with sticking the rollovers through the playfield at all. I ordered a few and my initial tests seemed positive. They were easy enough to power from my 12V supply, and just acted like a normal switch once I added a pulldown resistor. The one issue is that I'm using a switch matrix, so I needed some way to interface these 'constant' switches in. I designed yet another little board to go under my playfield which would basically just hook 4 proximity switches into the matrix

I designed some simple 3D printed mounts, and replaced all my rollover buttons
This wasn't quite as well thought out as I'd like, and I had issues fitting them into a few places. I was able to get around that by using some 12mm sensors in a few positions instead of the better range 18mm ones, but the detection of the 12s isn't quite as wide as a star rollover would be. The biggest problem is the rollover in the shooter lane. The 5 bank of drops doesn't leave much room between the rollover and the wall, and the area is just wide enough that the ball can sometimes worm its way past without triggering it. I may have to look into cutting my support rails a bit to make room if this doesn't work out, but I'll see how noticeable it is first. Since I eyeballed the entire cabinet without any planning I've been leaving about 5/8" room on both edges of the bottom of the playfield through the entire length so that nothing could possibly obstruct the support rails, but it could be that this area is far enough forwards that I don't need to worry about it.

Overall these proximity sensors are really cool, and if I'd known about them before I started building my whole playfield might be completely different. I could see myself avoiding rollover lane switches entirely, and maybe some of my hanging gate switches on shots too. The one downside is how tall they are. Compared to the very compact sensors I've seen on the Alien pinball machine, they really obstruct stuff under the playfield, and there's a lot of stuff like mounting them sideways in ball guides and stuff that you could never do. Once I get another shipment of spares in I'm going to chop one open and see if all that size is really needed, or if it's just a big empty cylinder to fit some standard industrial form factor or something...

Posted Tuesday, November 16, 2021
at 11:43 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 78

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



Having no luck with the flipper resistors, I went to the nuclear option regarding the heat buildup under the playfield, and installed 6 computer fans over all the holes on the cabinet to provide some airflow. Of course, it somehow had zero effect. So, as a last ditch effort, I ordered some PET-G to make a new playfield covering, thinking maybe the acrylic was the issue. To further correct some of the issues with my previous acrylic plastic, I took some rubbings on a large piece of paper and got it scanned at staples.
I'd done similar before with a piece of paper that I'd punched holes in to mark the positions of screws, etc, but some of those were missed or didn't come through well, and I'd also added the holes for all the screens since then, so I needed an update. Based on that, I made an updated CAD file:

Sourcing the PET-G at a reasonable price was a bit of a pain, so I didn't want to waste it. Luckily, I found that I could make serviceable test cuts with my CNC router on plain paper, so I did a few iterations with that to fine tune things. The cuts weren't perfect (rough edges, occasional tears) but it was accurate enough to be useful
Once I was satisfied with all the positioning, I cut the full playfield in PET-G
After reassembling everything again, I did a test game..... and the PET-G buckled just like the acrylic.

So I needed a new approach. Long term the clearest solution here is just to glue everything down, but I don't have any art ready yet and I'm not sure if I could apply and later remove the glue cleanly without damaging the wood. I'd been hoping to eventually cut a new playfield wood with the CNC, but as I continue to have problems with the depth of cut with the PET-G I don't have much confidence in getting that working quickly, so I'm still stuck with my original hand-cut plywood right now.

So I decided to go the other way right now, and instead of attaching everything down even better with glue to prevent the buckling, I decided to just attach as little of it as possible, and make a plastic more like the standard playfield protectors sold for other pins. The new protector would only be held down at three positions (the three posts closest to the center of the playfield), which should keep it from moving, while allowing the plastic to expand/contract as needed to keep from buckling.

Originally I'd rejected this idea when starting to experiment with the plastic covering, as I didn't want the ball to 'sink in' to the empty areas over the screens. But that was also with a thinner material. I'm now using 0.06" plastic, which is much more rigid, and doesn't seem to bend much as it supports a ball over the 9" screen even without being attached down at both sides, so I think it should still play fine.

Now... more test cuts!
Unlike with the full plastic where I only needed to worry about the holes for the screws, here I need to match up to every contour of the ball guides, etc. Which of course I mostly bent by hand/eye and don't have any accurate digital files for. And of course I didn't think to etch them onto the plastic when I got it scanned either. Not a big deal though. I can give even 0.2-0.3" of space around the edges of things safely without affecting the ball (although it looks a bit weird), so I don't need to be super accurate here. And thus, I cut another sheet of PET-G. And also order 2 more spares since I'm now out of stock and I hate to wait for things to ship.

Some things weren't quite as accurate as I thought, but in the end there weren't any major issues. Only two places touched the edges of the plastic, and since it's PET-G it's easy to trim by hand

So now I start reassembling the whole playfield AGAIN to make sure that this still all plays fine. I'm fairly confident this should work though.

Posted Tuesday, November 16, 2021
at 11:43 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 77

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



For a long time now I've had my start button doubling as an action button (I disabled restarting a game, and then made the start button trigger the action button code snippet once the ball has been plunged), which has been a bit annoying, and hopefully is part of the reason why playtesters keep forgetting I have an action button (doh!). I've also been stealing a lockdown bar from my Whirlwind whenever I do playtesting because... I don't have a lockdown bar for this game!

What I did have though is a really rusty spare lockdown bar sitting around. So I sandblasted it, then following McSquid's advice from his Sonic homebrew, drilled a hole in the bar, painted it black, and successfully mounted a flipper button in it using a 3d printed bracket.

Then I had to get a switch in there!

No problem, just drill two holes in the receiver to mount it, and then squeeze a switch in (with less than 1mm of spare room), snake some wires down, and wire it up. Working good so far, we'll see how it holds up during play

Posted Tuesday, November 16, 2021
at 11:42 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 76

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



Small updates...

Added a bunch of high scores to the attract mode. Besides stuff like a regular leader board, "best spinner rip", "most hands won", etc I also added a 'lowest scores' board for fun, since technically players can do so bad at poker that they end up in the negative. Could be an interesting thing to compete on!

Had another playtester over for a few hours of gameplay. I noticed they weren't really reading some of the mini screens much. Part of that, I think is just because they're generally really weird. It's hard to get used to looking all over the playfield to see what the writing says. But there's a second issue, which is that some screens were just hard to read. Part of this is due to the viewing angle I think. Displays towards the back of the playfield are both farther away and at a more extreme angle, so they lose contrast. Both of those make them harder to read. But the other thing I realized is that my larger rectangular displays were much dimmer than the smaller square displays I was using for the cards themselves. Each of these displays has a BL pin on them, which is supposedly for the backlight, but I was never able to find much documentation about it, so currently I have it disconnected, and the backlight does seem to work. I wondered if maybe the larger displays needed some extra power on that pin or something, so after failing to find any solid info, I gave up and just started sending random signals in to see what happens. It seems like the BL pin is an active low 'disable' pin to turn it off. Not really useful to me. But while trying to find documentation on it, I also saw some places talking about 3.3V vs 5V. Apparently the actual controller chip on these display boards can run off either voltage, and some manufacturers include level shifting chips so either voltage can be used to communicate. But again, I had no documentation for my boards, which I'd sourced from a random shop on ali express from china in bulk. So I figured, only one way to know for sure!, and just hooked one of the displays up to 5V to see if it smoked or not. Luckily it worked fine, AND got brighter! So I had to rewire all my displays get 5V for power instead of 3V :/

Playtesting also revealed a lot of switch issues. My modified small rollover buttons keep getting stuck in a few places, leading to the game going crazy or balls getting stuck, or sometimes just missing switch hits. I'm hopeful that when I get my CNC fixed and cut a new one, I can align these better, but I'm getting really tired of dealing with issues regarding this. Need to come up with a more permanent solution. I've ordered some proximity sensors to play with, and I also have some other ideas regarding the rollover design to play with.

Around the third hour of playtesting, my new thicker acrylic playfield cover started buckling slightly I'm not sure what causes the heat to do this at this point. I left it for like 8 hours plus with the game on, and had no issues, but now after a few hours I'm having issues? My only other thought at this point is that maybe it's the heat of the flipper coils themselves causing the issue. I've noticed that, especially after long games requiring lots of cradling, the lower flipper coils get quite hot and you can smell them sometimes even, despite the EOS being adjusted properly. I think this is due to the capacitor I've added to the power supply to give them more power. I've ordered some high wattage resistors to attempt to wire in series with the hold winding in a way that they'll reduce the strength of the hold circuit (which is already plenty strong) without affecting the power winding. If that doesn't work, then I may have to mount some tiny fans like people are doing on newer games in order to cool them off.

On the subject of heat, I've also gotten some 120mm computer fans to try to get some airflow moving through the whole cabinet. Even if running the electronics minus the flippers isn't enough to affect the playfield, it still does get quite hot in there and I don't like it. I've also realized that my RPi is mounted upside down on my MPU board, which probably isn't helping things. RPi 4s apparently already run hot, and I had installed some aftermarket heat sinks on mine, but a passive heat sink on the CPU doesn't matter that much if it's upside down. So I've designed a new version of the MPU board which will mount above the RPi to fix that. It should also give me enough space to give the RPi a small dedicated cooling fan if needed.

Pintastic New England has announced their next show will be this November, so bringing the game there is my new goal for the machine. I think it's achievable, in some form, but that means it needs to be able to survive a full day of the public playing it without me being around. At a minimum, I need to fix all these ball hangups. That'll mean fixing some switches, tweaking a few areas of the game slightly, and installing plastics and an apron in case of air balls. I also need to get the action button installed on my lockdown bar to get that presentable. If I can get the game bulletproofed, it'd also be really cool to get some cabinet art, but that might be beyond my capabilities right now. Time will tell...

Posted Tuesday, November 16, 2021
at 11:42 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 75

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



When I started working on this machine, I had a pretty simple power system. 3V for my boards, 5V for the RPi. Both coming from an ATX PSU. 25V for solenoids from an old gottlieb transformer. Power switch turned everything off, as normal, and I added an extra switch inside to cut the high voltage if necessary. A few early mishaps with coils locking on while the playfield was down made me realize the high votlage switch inside wasn't that easy to access, so I added a secondary power switch on the bottom for the high voltage. Very useful, I recommend that for any homebrew... Then I added 12V for the screen. And then 12V for the audio amp. Then another 3V line for the mini displays. And another 5V line for the LEDs. And another 5V line for the second RPi to power the mini displays. And another 12V line for the light strips. Each of these had its own fuse, etc, all coming from the ATX PSU. Luckily I designed a power splitter for the ATX-24 connector that could support all that, which has somehow managed to be future proof enough to keep me going and keep everything vaguely organized. Then I had to move each Pi to its own separate supply, due to noise issues coming into the amp.

However, there's a problem with that. I have three separate processes across my two Pis that currently need to be manually started, as I haven't made them automatic yet, and they sometimes need some massaging. My Pi also has a weird issue where about 1/4 times you power it on the OpenGL drivers just... won't work. I can't find any solution for it, so my only real option is to just repeatedly reboot the Pi and restart the processes until they work. Plus I have another weird issue that I've never been able to track down where the Pi won't boot if the cabinet switch matrix returns are connected. Can't figure out what could be causing that, and I'm hoping that a new MPU board revision will magically fix it. But in the meantime it means that, when I turn the machine on, I need to first reach in and unplug a connector, wait 5 seconds, then plug it back in. Then I walk over to my computer, SSH in, start all my code. If the driver is dead, I need to reboot, then pull the connector again. Sometimes this can end up being a 5-10 minute ordeal. My solution? Just don't turn the game off! So instead I reach in and unplug the LED power supply, light strip power supply, and mini display power supply. Then I grope around and find the power button on my screen and turn it off, and then I reach under and kill the high voltage. Game now appears 'off', but the Pis are still running. Easier, but it still leaves me in a situation where sometimes I avoid playtesting my own game because it's too much of a pain to turn on! So that had to stop. I realized that, in the end, all the systems I want to turn off are coming through the ATX supply, and my Pis are on their own supplies, so really I just need to turn the ATX off. If I'd planned this from the beginning I probably would just install a third power switch, but I don't feel like taking everything apart again to do that. So instead, I replaced my internal HV switch (which I never use anymore) with two extra 'service' outlets, and plugged the Pis directly into them. So now the Pis are just 'always on' as long as the game is plugged in, which is fine with me. Meanwhile I have a primary power switch which kills everything in the game except the Pis, and an extra switch to turn the HV off if needed. Much better

Posted Tuesday, November 16, 2021
at 11:42 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 74

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



In between these playfield changes I've been making a bunch of tweaks to the code. I added another multiball, rounding out the main hands (straight, flush, and full house). Added a mystery award which is really fun but hard to explain via text. Lots of tweaks and bug fixes. But mainly I've been working on sound!

The game now has more than 100 sound effects and callouts (and still many to go). At first I was agonizing over trying to find some good sounds that fit everything well, etc, but I've realized that you don't need a 10/10 sound effect to add quality to the game. Even a 5/10 sound effect is way better than no sound effect, as long as you've got them everywhere. Sadly I've also realized that making 5/10 sound effects is way harder than I'd have guessed. I've spent a bunch of time with a mic, a few poker chips, and a deck of cards, making random sounds by hitting them against each other, etc, trying to get some good, real, 'poker' sounds to put in.

On the software side, I did some research into how other games handle sounds. Playing one sound is simple enough, but it seemed like if I just played every sound that came in (and every call out, etc) things would get messy. You never want two callouts at once, and I figured you may not want multiple sounds at once either, so there needs to be some system in place for that. Sadly, it turns out that getting Java to play a sound, and then kill that sound mid way, adjust volume on the fly, or even just get the length of the sound are all more complicated than you'd expect. I ended up writing a custom mixer to combine a music channel, a voice channel, and a few sound effects channels together on the fly, which gave me the level of control I wanted. Currently I've got a simple system set up where, if a sound is playing on a channel, nothing will interrupt it (after like 50ms). If you try to play a sound but there's already another one going, that new sound is ignored. If two sounds come in at once (which happens a lot since I might have the base game make one sound effect, but then the mode you're in at the time makes another), I just choose the longer one. Originally that was a hack until I could code some proper 'priority' system in to let me manually order the sounds but so far it's worked surprisingly well so I haven't had the need to go further. I've also implemented some ducking, so the music and effects will get quieter when there's voice playing, and the music will get quieter when there's effects playing. Took a bit of play to get that to sound natural, but once it did it worked well.

Posted Tuesday, November 16, 2021
at 11:41 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 73

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



Sometimes to get an idea as you fall asleep saturday night.... and then spend your sunday making it work

My upper magnet has never worked how I wanted. My goal was basically just to be able to shoot the left orbit and feed the upper right flipper. Magnet couldn't grab the ball. So I added the up post. That wasn't 100% reliable at even catching the ball, and when it did, the magnet still couldn't grab it somehow. So I cut the hole all the way through the playfield to give the magnet more power. Didn't help at all. When I made the new plastic playfield, I didn't even bother cutting a hole for the up-post. My thought was, instead of shooting the left orbit to feed the magnet, I should be able to shoot the spinner, and use the spinner to activate the magnet, since the ball would basically be in perfect position over the magnet when the spinner switch closed. But that, of course, didn't work at all. Magnets suck! I ripped out the magnet. Maybe I should just forget this entire idea about feeding the upper flipper. I basically only ever used it for one of my four multiballs which had a jackpot only hittable from the upper right flipper; it seems like a waste to put a whole mech in just for that. But the multiball was based entirely around that upper flipper shot (it's basically a lawlor throwback themed multiball), so I'd have to rewrite that whole multiball somehow. Plus then I'd have no need for the target under the upper left flipper which I've gone to a lot of pains to implement. There'd barely be any reason to have the upper flipper at that point; all it'd be useful for is trying to feed back to the upper playfield area if you drained out of it to the right.

So I needed some other way to feed the upper flipper. Before, on the left orbit, approach, I'd tried to figure out how to work a diverter in there, but there just wasn't room any way I could find. While watching the magnet fail to catch the ball via the spinner shot I thought, it'd be cool if I could like, have a raise-up captive ball. I've always liked how captive balls feed flippers but you don't see them in too many games. But there was no room in front of the spinner to try to make something like that due to the screen+lights. And I couldn't really put it behind the spinner since I had a giant hole there from the magnet and you wouldn't be able to see the captive ball well to aim for it. But I figured you don't really need a captive ball at all. Really you just need a wall for the ball to hit to fall back to the upper flipper. A single drop target that could raise up would be cool, but I think the rebound would be too fast. I really just want to deaden the ball and let it gravity feed for the shot to be makable.

Thus:
In the up position, the ball goes underneath just like normal. When it's down it sorta catches the ball and lets it fall back down again. It isn't always a perfect feed but you can always get a flip at it

Posted Tuesday, November 16, 2021
at 11:32 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 72

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



I'd been considering something similar, and then I saw these on the Sonic Spinball homebrew and got a link to the strips, so I added some light strips along the sides for GI. Actual GI bulbs had never really been in the plan, since they'd need to squeeze into some tight spots. Plus there aren't that many spots to put them, which confused me a bit at first. When you look at the playfield though, other than the slingshots and around the ramp, there's pretty much no spaces where a GI bulb could even go. When designing I like to make the most of the space, but maybe it's a bit too far?

I got some plain warm white LED strips, and some V channel guides for them:

Then I 3D printed some supports for them that stick into the triangular hole in the back of the channels
I mounted them onto the side rails, instead of to the cabinet like Sonic + Pinstadiums do, so there's no need to remove them when lifting the playfield. They sit about a millimeter below the glass


The illumination doesn't cover the whole playfield quite as nicely as I'd like, but if I wanted anything else I think I'd need to custom design some channels to aim them at like a 30 degree angle instead of the 45 or 0 angles commercially available.
If I'd planned these from the beginning, I might have made some custom metal channels, with some stronger metal mounting posts, so that I could actually set the playfield upside down on them for servicing (and maybe some spare attachments at the front to make it even). I like the idea of the playfield having complete protection when removed from the cab. I've got the support rails on the bottom covering that side, so I can easily pull the playfield out, set it down on a table or on end, and not worry about the mechs, but currently if I want to set it upside down I need to use the wooden back wall and manually install some more wood posts to the hangers in the front, which isn't too convenient.

I'm not sure if that'd be worth the effort though, and I'm not sure how satisfied I am with this technique. For a whitewood like this that I've been winging the design on a bit, they're really nice. No need to make concessions for them in your plans or worry about wiring, etc, but they also have an annoying glare on the playfield. It's especially noticeable here since I have a perfectly flat acrylic sheet on the playfield, while a clearcoat would probably be a bit more subdued. The glare isn't in the main play areas, so it's not a deal breaker (they're better than no lighting!), but I'll have to think more about other options or tweaks to this in the future

While the coverage isn't completely even, these new lights do illuminate the back wall (or lack thereof!) though, so I'll need to think about that more at some point. Technically you could airball right over the back wall and into the cab currently, but I've never seen that happen. It also illuminates that there's a ton of dust on my playfield :/ Sadly that's what happens when your game sits for months with no glass on it, and I don't think that'll be changing any time soon. I may need to station a shop vac nearby for convenience though.... There's still a lot of ball hangups, etc currently so I couldn't really have the glass on for too long anyway. Actually I don't even have a sheet of glass for it since I stole it for another game to replace some non-tempered stuff; and I don't have a lockdown bar for it either. At some point I'm going to need to put a focus on getting some glass, getting a bar, installing an action button, and then dealing with all the stuff that keeps me taking the glass off: I'll need to make some plastics (easy, but may need to swap some posts to mount them), add some more stuff to prevent airballs from getting stuck places, make an apron of some kind, etc.

Posted Tuesday, November 16, 2021
at 11:31 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 71

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



While I had the playfield apart, I also made a few layout tweaks

This is the guide for the upper left flipper. Old guide on the bottom. It had a split in it for a standup, but it turns out the flipper can't hit that angle. No matter how I aligned the eject plunger, I couldn't get a clean feed past that gap. So I made a new, one piece guide and installed it. Now the ball comes down nice and smooth to the flipper. Almost too fast, to be honest. I need to play with that mech a bit, see if I can get it to give a slower kick.


A bit hard to see here, but I added slots for adjusting the height of the left outlane posts. Eventually I'd like these to be slots in the wood too, with machine screw posts, so they can be precision adjusted, but right now the area underneath is too messy to safely install that.


The center post on the right side got a horizontal cut, since it can't really be moved vertically due to the feed from the shooter lane. Also replaced the upper end of the shooter/outlane divider rail with two mini posts. I'm not sure how that will affect the play in that area, but hopefully it does something. Previously it didn't seem like there was much to 'do' over there. You'd just watch the ball balance on the center post and fall one way or another, and any ball hitting the wood rail would just die and go down the outlane. So I'll see how this goes.

Posted Tuesday, November 16, 2021
at 11:31 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 70

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



Finally got the lights all working, and coded a simple attract mode animation for them. Originally I was trying to use an existing server I found for controlling ws2812 leds, but it kept crashing and wasn't very suited for pinball animations, so I coded a simple server myself which just handles a light being on, flashing, or pulsing, with settings for frequency and phase. I think I will need to tweak my colors a bit though. Not sure if it's because of the specific leds I got, or the way the opaque white inserts are coloring it, but everything feels a bit 'pastel'...

The downside to doing all your leds as one giant strip, I guess, is that if you want to change them later it's more complicated. And of course, once I got everything together here, I realized I'd forgotten to install a light for the lower playfield diverter. So I guess at some point I'll need to cut a bit from my left over led strip, attach that there, then cut my existing strip somewhere, and run the data line over to the new led and back again.

I'm also thinking about maybe having a sort of 'wizard mode' accessible after you get all the main hands (at least straight, flush, full house, since technically those cover all the 'lower' hands too. maybe four of a kind, but it's hard to guarantee there's ever a deal with 4 of the same card), so it'd be nice to have a few more inserts in the barren center area between the screen+slings for that. Just when I thought I had all the lights/etc figured out!

Posted Tuesday, November 16, 2021
at 11:30 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 69

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



I'd been getting tired of using the projector for everything, and with the lights taking away half of its use, I figured it was a good time to get to work on the other part of that: the cards themselves. I'd realized early on that having all the cards just printed on the playfield, unchangeable, would have a possibility for people finding certain cards to go for every time which would make the game less fun, and having the projector able to deal a random set of cards onto the playfield solidified that worry. And then I found some cheap LCD displays on ali express while searching for the main screen I installed before
Turns out they were slightly narrower than the spacing on the drop targets:
Thanks to the provided example code it wasn't very hard to get one to display a card using a raspberry pi
But could you drive more than one easily? I made a little board that had a shift register on it to control the CS line of the display, so that I could theoretically wire up to 8 displays to it


So far so good! Now, could I fit those displays in front of the targets? I did some measurements of the 3 bank in the middle and printed a bracket

And they fit! barely.
I programmed a simple tcp server to control them, and hooked the 3 displays into the game
Alright, proof of concept complete. Time to go way too far with this.

I'll need to custom make a bracket for every bank in the game, since they're all different manufacturers+sizes

And since I'm already getting into this, why not throw some other single displays around the playfield?

Now, can I actually drive them all? No. I lose signal around the fourth board. A lot of learning about signal integrity and I've got another version of my board with some termination resistors and a buffer chip to redrive the signal between each board
And with that, I can barely get all my displays to work

So I cross my fingers and cut a lot of big holes in my playfield. The amount of missing wood at this point is starting to concern me a bit, but it seems to hold up okay when the side rails are attached.
Wiring them up is also fun. So many ribbon cables! Almost looks like a Spooky game...
And once I finally got the whole playfield reassembed...
Success!

Posted Tuesday, November 16, 2021
at 11:29 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 68

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



Still working on a bunch of stuff so I don't actually have any top side pictures yet but..... light!

The funny side effect of just trailing a light strip around the playfield is actually looks cool underneath too.

I ended up using 126 LEDs worth of 30/m strip to reach all ~30 inserts on the playfield. Besides from a few places where I didn't plan for lights and had too many mechs in the way, it was pretty easy to mount the strip over the the holes. The budget pack of clips I found are a bit too big, so there's still a bit of back and forth play, but I don't think there'll be enough movement to cause any issues.

I hooked the strip up to a dedicated 5v line+fuse coming from my ATX PSU, and it seems to be lighting fine with just that power coming in at one end (I was sorta expecting needing to provide more power somewhere along the length), even with all the lights on (which will never happen in practice). I had to make another little adapter board for my RPi-powered MPU to add in a 3V - 5V level shifter since the RPi only puts out 3V, but that seems to be fine for driving the whole strip, with an added 4ft of wire between the board and the beginning of the strip. Time will tell whether the electrical noise interferes with the lights once everything is playing, but hopefully they'll be okay (plus I plan to refresh them at 30Hz so any glitches should clear up quick).

Posted Tuesday, November 16, 2021
at 11:20 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 67

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



Got the inserts from PBR, luckily they're the same size I was planning on, so I went ahead and cut all the arrows.
Midway through I stumbled upon this technique, drilling three holes through first, then routing out the rest using the guide, which allows me to do all the routing in one pass (before it was three passes since I kept needing to stop and remove all the dust, etc). Then once it was cut and the insert test-fitted, I'd take the guide away and hand route between the three holes to leave a good open area in the center for the light.

I was hoping that the circular inserts would match up with my forstner bits, but not all of them did. The smallest one (5/8?) are perfect, a nice snug fit, but the 3/4" are just loose enough that they'll fall out from gravity if there's any vibration. I'd like to get these all press-fit if possible so I don't have to worry about gluing them, so I'm going to try to make another router guide for the 3/4"

Posted Tuesday, November 16, 2021
at 11:19 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 66

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



Got the LED strip today. Was surprisingly easy to get working using adafruit's python library, worked the first time. Sadly I don't want to use the python library so I'll need to explore alternatives for integrating it with the rest of the code. I did some experiments with inserts. The circular ones lit up fine, but the larger ones like the arrows had a bit of coverage issues.
It's hard to get good pictures of leds lit up, but

Here's a clear triangle insert
And here's an opaque one

The clear one lit up a bit more evenly, but it didn't really look that good, you could clearly see the hot spot where the led was located. Surprisingly I think the opaque one looked better overall, and other colors seemed less washed out, which is nice since that's probably my only option...

I then played around with led placement. Putting it more towards the center or ends didn't help much; the ends were still pretty dim. What did help was cutting a bigger hole. here's a single led, positioned similarly to the previous photo, but with almost all of the insert cut through the playfield instead of just one hole the size of the led

Probably good enough for me. I'll need to come up with a better way to cut those inner holes out, maybe another 3d printed router guide or something.

I also played with two leds under the same insert

This looks a bit better than just one, but not as good as I was expecting. The hot spots seem more pronounced. I'm not sure if I'll be able to position the strip to hold two leds inside the arrow or not (the clamps haven't arrived yet). This is where a lot of people seem to use multi-led boards, which might be worth it at least for the main shots? I'll have to look around

Posted Tuesday, November 16, 2021
at 11:19 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 65

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



Since I had the playfield torn down, I figured I might as well install the inserts too. I've got a big bag of random inserts I've collected over the years from different stores, so I started laying them out. To keep things simple, I used one size of arrow (1.5" triangle) and three circles. I think the circles can probably be done with a forstner bit, but the arrow will need to be done with a router. Taking some advice from Johnsonvillebrat, I designed a guide for my router
and a guide for the shape
It took about 10 tries to get the guide just right for a snug fit (a big pain, since each print took 3 hours!) but I eventually got it just right
and made my first cut in the playfield

....aaaand immediately ran into an issue.

Can you spot the difference between these two arrows?

One is wider at the tip! I sorted through my inserts and found out that half of them won't fit the guide I made, which also means I don't have enough of the correct inserts for the playfield. I was planning on making them all clear, uncolored, for RGB lights, but I don't have enough of those. So I went to order more.
...aaaaand no one stocks them! (unless I want to pay $5 each shipped from europe) What? A transparent arrow should be like, one of the most common ones needed. Pinball Life (who has a great selection of inserts for homebrew) has six colors... but no clear. And they don't have any plans for restocking. The best I can find is that PBR has some opaque white inserts available, but I'm not sure how that'll look since every modern game I know of with RGB lighting uses transparent.

Luckily, I had one of those in my assortment, so I figured I'd stick it over an led and see how it compared.

...which made me realize I have no RGB leds. In fact, I have no real plan at all for how to light all these inserts! Back when I was first planning out this electronics system years ago when RGB was still a bit new, I figured I'd just get some 4-legged RGB LEDs, and then just stick them in a matrix. Except I don't have any boards designed to drive a matrix. And after wiring up the switch matrix, I really don't want to wire up another whole matrix with double the wires. It seems like today everyone is using NeoPixels and other individually addressable, chainable LEDs (well, besides stern, but), so I started looking into what'd be the cheapest, easiest, least messy way to get some of those installed. Luckily when I designed my MPU I added a spare connector for the 3 extra unused GPIO the RPi had, and I made sure that one of those was the DMA pin that's commonly used to drive these LEDs from a Pi, so I think I can drive them. If not I can get a FadeCandy or something. It seems like a lot of people are just buying FAST's individual LED boards, but they're $1.50 each, and need wiring to connect them all. So I ordered 5 meters of addressable LED strip (150 LEDs) off eBay for $15, and some mounting clips for $5. I'm hoping I can just string this through the playfield to reach all my lights, and use the spare LEDs in between as free wiring (just don't turn them on). Maybe that'll work, or not. I can always find a use for 5M of LEDs at worst though.

In the mean time I've also ordered a bunch of opaque white inserts from PBR, since they're cheap and I needed some other parts anyway. Hopefully they light up well. Maybe the opaque inserts will give it a more retro feel? Of course, I don't know if the random opaque triangle insert I had lying around is from PBR or not, so cutting (and thus, reassembling) the playfield needs to go on hold for now until the order arrives so I know whether I need to design a new router guide

Posted Tuesday, November 16, 2021
at 11:18 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 64

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



Ran a test cut of one 4x5" area

It turned out fine, no obvious issues.

so I went and did the whole thing. I took one of my rough manual cuts, and stuck it down with a bunch of double sided tape. In retrospect I should have used thinner tape, as during the cut I could see the plastic flexing downward before the bit broke through, but it doesn't seem to have caused any issues with the cut.



My first time running a real job on the CNC, probably took about 40 minutes. Plastic seems to have come out fine, and it at least fits on the playfield.
Most of the holes are off center, but not outside the margin of error (I made every hole bigger than needed). There's a few places that need some correction, so I need to figure out how to do that. Aligning the plastic perfectly was a big pain, I don't think I could reliably get it matched up again. But I want to avoid doing stuff 'by hand' for risk of cracking the plastic. Maybe I'll need to use the router manually? Or try to run the CNC with manual control. Before I bother with any of that though, I should probably secure this down again and do some more heat tests.

I went in multiple times to try to do the corrections to the layout, but something just wasn't making sense. The corrections weren't all in the same direction, but different parts of the playfield tended to all need correcting in the same direction, and half the time that direction was opposite of how i'd already corrected those points before. In addition, the way I lined up the plastic so that it lined up with holes the closest resulted in it not being parallel with the edges, which didn't make sense either. When I lined it up with the edges of the playfield, right to the corners (where I know it should all match up), none of the holes lined up at all. So I stopped working on that until I could figure out what was going on. I measured various parts of the plastic and the wood playfield, and checked them against my CAD drawings, and they were all accurate. Then I got a t-square out to check if maybe my playfield somehow wasn't square. Nope, playfield was square. But the plastic wasn't! It had a 3/8" skew to it along its entire length. There must have been something wrong with the setup of the CNC causing it to list to the right as it moved up the playfield, so I'll need to figure that out. Never noticed in my test cuts since all of them were smaller. So that plastic is a loss for any real work. But knowing that it's wrong, I don't have to worry about fixing it the right way. So I just got out a router and adjusted all the holes by hand to line up enough. I'll reassemble the playfield on this bad plastic for now to test out the material.

Posted Tuesday, November 16, 2021
at 11:11 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 63

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



But before I can cut some new stuff, I need some drawings to cut! I took my scan of the original playfield, and converted it back into a cad drawing (what a pain!). Then I got that printed out on paper at 1 scale again, tore down the playfield, and laid the paper down on the playfield to verify everything, since I wasn't sure if the scans would be "square".

Sadly you can't see through paper (it would have been amazing to get this printed on something clear but as always I'm being cheap), so I had to use a small screw to search out all the holes in the playfield again for comparison

Some parts were spot on
Some were off, but very consistently so
And some things were so far off I don't know what could have happened...
Overall, the stitching seems to have worked pretty well, but not good enough to really be a go-to thing. In the future I'll need to be more vigilant about cutting stuff exactly matching the cad, and adjusting the cad as I go when anything diverges to prevent this.

I spend most of my day off today going through every hole again and manually adjusting my cad drawing (which the paper was printed from) to account for the discrepancies, so hopefully I'm now good to go. I'd like to avoid having to get another throwaway paper printed to verify all my changes, and I've got 3 sheets of acrylic ready to go, so I'm tempted to do a few test cuts on leftover stuff, then just get cutting and see how I do. Probably not the smartest thing to do but at some point you've gotta stop preparing and just jump in, and the cost of failure is theoretically pretty low (or it would be if I could find any reliable source of plastic locally, grr)

Posted Tuesday, November 16, 2021
at 11:11 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 62

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



Two months of no real progress on the game, but: I've got a CNC router!

It's... currently sitting on top of the bed in my spare bedroom, because I horribly underestimated how big it would be. But that's fine, not many guests during COVID. I haven't done any really big serious work with it yet, but it seems to work fine for my small tests I've run so far, so I don't think anything should change much.

I did some test cuts using a straight edged router bit (not sure the correct term for this), which was recommended for cutting plastics (since it doesn't have a helix to pull up the material). With a spare bit of lexan, it didn't do too well, sorta ripping up the edges and melting them a bit, similar to the issues I had cutting my lexan by hand with a drill. I got a sheet of 1/16" acrylic and tried that, and it cut much better. Not perfect, but definitely presentable. The only issue is that acrylic has a tendency to crack and shatter randomly. The router bit hasn't caused any of that yet, but when doing a whole playfield it could potentially cause an issue. I also tried another scrap of plastic I had on hand (which I think is PET-G, but I didn't label it), and it cut super nice. I'm trying to source some PET-G sheets locally to test out but I haven't found anything so far, so I'm gonna go ahead and try the thicker acrylic first. Acrylic also is (supposedly) what 70s+80s games with plastic playfields used, and what other homebrews have, so I'm still hopeful it'll work.

Posted Tuesday, November 16, 2021
at 11:02 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 61

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



After a few multi-hour sessions with the glass on, the plastic has finally started buckling. Worse, after I left it to cool off for a day, it's still not lying completely flat again. I assume if I stripped and repopulated the whole playfield I could fix it, temporarily, but not a permanent solution...

I've been told that this method worked successfully on some homebrew pins, but using 1/16" perspex (acrylic). When I went to my local plastics shop to buy some, they recommended I use lexan instead for this application, as it shouldn't react to heat any more than acrylic and would hold up to the pinball better, but months later when I finally unboxed the sheet and measured it, it seems to be 1/32" per my calipers. So maybe a thicker sheet would work, or maybe the material is wrong. Or maybe I'm missing something else... I don't really want to hand cut another one of these after all the effort the first one took either. Maybe I'll shell out to get one laser cut, if I can get a good cad file together...

I've also ordered a CNC router (https://www.v1engineering.com/lowrider-cnc/) that hopefully I can eventually use to cut new playfields and maybe plastic sheets (or even longer term goals, I get my own laser cutting head to attach to it), so maybe I'll wait on addressing this issue for a while. Moving back to a clearcoated playfield is always an option, it'll just add a ton more complications and steps to deal with...

Posted Tuesday, November 16, 2021
at 11:00 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 60

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'




Got the playfield reassembled and have been playing a bunch of test games. No buckling on the main playfield at all. I've got a slight bubble above the upper left flipper, I think I just tightened stuff down wrong though, doesn't seem to be changing. Have to be very careful no screws are rubbing against the edges of their holes, and to attach stuff in a 'wave', to make sure the plastic lies down flat. There's a slight drop in the plastic over the screen from the weight of the ball but not enough to affect its travel or anything.

Plays much faster with the plastic compared to the paper (who would have guessed?). I'm not getting occasional airballs off the center bank, which isn't great, and some balls are flying right over the eject hole. I'll have to make some air ball guards, and might also turn down the flipper strength some, since it's a bit too much in some places. If you hit the left target on the center bank from the right flipper it rockets down the left outlane too fast to see.

While reassembling I also noticed that some of the post screws are starting to strip. Some of these should definitely be machine screws, but that can wait.. for now I'm just upgrading to longer screws, since the ones I had were only going 1/4" into the wood.


The upper magnet continues to cause me issues. Despite doing multiple tests showing that it could grab a ball from ~2.5" away with no wood in the way, it still can't pull a ball reliably off the post for some reason... It might work better if I had the post above the magnet instead of below, so it'd have more time as the ball drops, but it's probably still be sketchy. Again I wonder if having a large metal core covering this whole area would work better, or if having the magnet under just 1/32" of plastic is equivilant....

If I position the magnet at the far right, it can grab the ball 75% of the time, but it drops it too far to the right and it doesn't feed the flipper well. If I position it more to the left it feeds cleanly, but can't grab the ball. there's about 1/8" sweet spot where it mostly works, but anything can throw it off, definitely not reliable enough.

Additionally, I'm also having issues where sometimes the ball comes around the orbit so fast that it actually bends the post and gets wedged in between the post and the wood on the right, sometimes also lifting off the playfield somewhat. If I can't get the post more rigid, I'll have to abandon it since it's getting the ball suck...

Posted Tuesday, November 16, 2021
at 10:29 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 59

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



Installed the upper magnet. Needed to cut a 3" hole to fit it, but luckily that just barely left holes for the surrounding stuff that was mounted there. Right below the nearby target you can see one hole where one end of the ball guide goes, which I'm half certain is going to rip apart at some point since there's so little wood left there. Tried to design the mount to hold the magnet slightly below the surface so it won't scratch the plastic, but not sure how that'll work when the magnet is active... maybe I should cut a circle of plastic to 'float' in between them or something? I feel like overall I don't want it to be too much lower, or it may stretch the plastic or something

Posted Tuesday, November 16, 2021
at 10:29 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 58

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



After a lot of careful measuring, it's time.

The fit I'm going for is very tight. I'm about 2mm from one of the drop target mounting points, and I'm going to need to relocate one of the slingshot switches slightly, move a fuse block, and make a custom mount for the magna-save, but, it should work.

Printed this magnet bracket, and cut a small stick of 3/4" iron for the core (I think this is the right metal...)

20 agonizing minutes later, I have a hole

It fits! Barely. You can see the penciled outline of the drop bank on the bottom right, and the currently floating fuse block on the bottom left. I had some room to the top (left side of the playfield) I could have moved it to if necessary, but I wanted to keep it centered between the slings/flippers if possible

I then mount the control board very professionally, and hook it up. Success!
Lets get a game running...

The viewing angles aren't the best but I think it should be okay. Will have to wait until I get it in the game for that though. The supports are a bit too thick and stick out of the playfield, so I'll need to space those or something. Not sure how I messed that up, thought I specifically made them slightly short :/

Posted Tuesday, November 16, 2021
at 10:28 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 57

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



Reassembled and dropped it in the cab again for more testing.

Everything seemed to work fine. No mechs were sticking, no raising of the plastic anywhere. I left it sitting for a while with the transformer+electronics on in case that would trap any heat underneath, but nothing happened. I'm still quite suspicious, but I can't really think of any more testing I can do at this point, and the playfield does look so nice and shiny....

So I took the playfield back out, and disassembled the whole thing again. I'm getting very fast at this, but it's still a pain. One thing I'd try differently next time is the side rails. Currently they're under the plastic, but I think it'd be fine to have the plastic 1mm away from them. This'd save at least a quarter of all the screws I need to remove when taking the plastic off, and prevent the playfield from having time to sag while the rails are removed. Within a few hours of removing them there's a noticeable 1/4" dip in the middle of the playfield, which is more than I'd have expected, especially with all the drop target banks already removed... I assume my playfield wood just isn't as sturdy as what manufacturers use, but nothing I can do about that

With the plastic removed and everything stripped off, I have some updates to do that I've been putting off:
- the right controlled gate for the top lanes needs to be moved about 1/2" to the left to prevent ball hangups
- the right-most upper lane needs a new rollover drilled in line with the others, since previously it only had a 'bottom' row switch
- need to add lane guides to the upper lanes so the ball doesn't fall the wrong way
- the target under the upper left flipper needs some tweaking. The hole isn't big enough to fit it through right now, so I need to extend it, and I want to reposition the guide wire below it to give a better feed
- I've removed the upper left target (it was sort of under the ramp above the upper left flipper) since it can't be hit due to the pop bumper being replaced with a rubber (it wasn't really hittable before either), so now I can make a new guide going from the upper eject hole to the upper left flipper that doesn't have a gap in it for the target, which will hopefully improve that feed.
- widen a few holes and slots slightly since some mechs would occasionally bind a bit on the edges

Once that's out of the way, I'll move on to the fun part: cutting a 10" hole in the middle of the playfield for the LCD screen. No chances to mess up horribly here, nope...
And then I can cut another 2.5" hole for the upper magnet and finally get that installed again!

Posted Tuesday, November 16, 2021
at 10:27 AM


Tags: Blog Post, Pinball, Project, P3,

Homebrew Pinball #3, Part 56

Cross posted from the original Pinside thread, this is one of many posts regarding my third homebrew pinball machine, creatively nicknamed 'P3'



No noticeable change in the plastic after sitting all day with the lights on it, so time to dig in. I started by just making all the holes for posts, guides, etc.
I've gotten pretty good at making clean holes, at least for smaller sizes, but for some reason they never seem to center well. Some I went to a bigger size, others I manually elongated by running the drill against one edge.
Luckily, with a new blade, making the slots and other straight lines isn't too big an issue. I score each side 3-5 times, then use a hammer to punch it out, and I get pretty clean lines (as long as I get the corners right)

Bigger holes cause issues. Once you get to about half an inch (or even 3/8 sometimes) the bits start to chew up the plastic. Depending on how bad it is I can sometimes clean it up with a blade but it's never perfect. I wish I had a better way to do these, but no method I tried (drill, forstner bit, spade bit, etc) was perfect. It'll be fine for a whitewood, but I think I'll definitely need to get a better one of these machine cut at some point if it all works out.

I'm finally at a point where I have most stuff cut out, enough to reassemble and playtest the game to see how everything works. I've skipped some of the guides, the drop target banks (since they're removed right now anyway), etc.

Posted Tuesday, November 16, 2021
at 10:27 AM


Tags: Blog Post, Pinball, Project, P3,

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